Avalanche Forecast Waterton Lakes National Park

Date Issued: Valid Until:

Parks Canada adam greenberg, Parks Canada

Avalanche Forecast

Mon Jan. 21st ยท 4:00PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Problems

Wind Slabs Wind Slabs
Deep Persistent Slabs Deep Persistent Slabs

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Considerable

Below Treeline

Danger Ratings Moderate

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Considerable

Below Treeline

Danger Ratings Moderate
Keep an eye on actual snowfall amounts on Wednesday. Strong winds and incoming snow has the potential to overload buried surface hoar and suncrusts.

Weather Forecast

Tuesday: Cloudy with scattered flurries. Snowfall amounts 4cm. Alpine high -10, strong SW winds.Wednesday: Periods of snow. There is disagreement on amounts in the models but we may see up to 15cm. Moderate W winds, freezing level 1300m.Thursday: Cloudy with isolated flurries. Freezing level down to valley bottom with moderate W winds.

Snowpack Summary

25cm of recently wind affected snow is sitting on either a suncrust below 2000m on solar aspects or spotty surface hoar in sheltered areas between 1600 and 1900m. This may be a problem layer as we see more snow this week. The midpack is strong in deep snowpack areas, but the facets lingering at the bottom remain a concern in thinner areas.

Avalanche Summary

A forecasting trip up the Akamina parkway revealed several small loose dry avalanches out of steep rocky terrain. A skier in the Fernie backcountry triggered an avalanche failing on the same surface hoar layer we are seeing in the park but was able to ski out of it. With up to 20cm of snow in the forecast we may see similar activity on this layer.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Problems

Wind Slabs

Wind Slabs

Wind Slabs will continue to build over a crust / surface hoar layer and may propagate farther than expected. Dig down and investigate the bond of new snow before committing to your line.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely - Possible

Expected Size

1.5 - 2.5

Deep Persistent Slabs

Deep Persistent Slabs

This layer likely requires a large trigger. Be cautious when transitioning from thick to thin snowpack areas

Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Unlikely

Expected Size

2 - 3